Adjustable seat and backrest unit for a swivel chair



FIG. 1 is a front view of the adjustable seat and backrest unit for a swivel chair showing our new design,

FIG. 2 is a bottom view,

FIG. 3 is a front perspective view,

FIG. 4 is a rear perspective view thereof; and

FIG. 5 is a side perspective view showing the seat and backrest unit in reclined position. 

The ornamental design of an adjustable seat and backrest unit for a swivel chair, as shown and described. 